Electromagnetic switch.



F.KRAT2, ELEcmoMAGNETlc swncH.

APPLICATION FILED DEC. 1I. 19H.

1,23 1,27 1 Patented June 26, 1917.

v/nmlssss A llvErJ-VDR 4 fable manner= and at the saine t'iiii'eutlieswitch UNITED STATEQAPATENT e OFFICE.

FRANZ KBATz, 0F STUTTGART, GERMANY. AssIGNoR To THE FIRM or ROBERTBOSCH,

U oF STUTTGART, GERMANY.

ELECTBOMAGNETIC SWITCH.

seciacation uf Letters raamt.

Patented Jane 26, 1917.

- Application led December 17, 1314. Serial No. 877,705.

To all whom it may concern.'

Bc it. known that I, FRANZ Kaa'iz, a subject of the Emperor of Germany,residing at and whose post-oiiice 'addressis Schlossstrasse 59A,Stuttgart, Germany, have in-4 rapid Hand without appreciablearcing4 uponinterrupting the circuit. Double p ole switclies'forths purpose shouldinaddition have uniform pressure exerted on the two poles 'in order tomaintain an effective cir-- cuit closure,-'and they should also producesimultaneous interruption at the two points iii 'the circuit. Theserequirements are espe-- cially important iii case the switch iselectromagnetically1 operated, first on acco'unt'of the comparativelysmall movement available, and secondly ou account of the Alimited*amount of power available.' y

. In the preferred form of the invention. I provide an electromagneticswitch in which these, characteristics are secured by making the` switchterminals with plane contact facesto contact with'yielding ingersof alswitch bridge. and by loosely mounting .a sleeve. to which the switchbridge is secured. on a rigid guide post. so that the armature shaft ofthe clectroiiiagnet in pressing down on the switch bridge witho'ut.connection thereto causes the switch bridge to tilt through the slightanglel thatI is necessary to engage the switch terminals with'uniformpressure; In this way. the contact resistance is maintained at asmall value when the circuit is closed,

and the lingers Vof the 'switch bridge inV a double pole switch may be'rapidly andsi? iiiultaiieouslydisengaged by a spring. Furthermore. b vcausing the armature. of the clcctromagiiet to bear loosely o n `theswitch bridge without being connected thereto, the

switch bridge may be insulated from the eleetromagnet structure in asimple and relibridge may be secured rigidly to the sleeve whichembraces the guide post.

In the accompanying drawings illustrating the' preferred embodiment ofmy invenion, 4

Figure 1 is a central cross section of an electromagnetic switch of thedouble pole type for controlling the circuit with which it isassociated; and

Fig. 2 is a section online 2--2 of Fig. 1. The armature sliaft is easilymovable in bearings in the ot-shaped body a, and it carriesat one end)a. clamp? for attachment to a'mechanical part, the position of which -isdependent upon the circuit connections effected bythe'switch. The other.end d of the. armature rests on an .insulating bearing member e carriedby the conducting switch bridge f. which is made up of a pluralityofVcopper ystrips bent'over to form yielding fin-V gers.` The switchbridgealso carries -the spring-mounted carbon contacts gdesigned to finally-break the circuit and take theiirc. The switch bridge f is'fast on 'ametal sleeve la, which embraces a rigid'post ti with slight amount. ofplay, the pin k in the post extendrotation of thebridge. Thecover'm-carries t io post z' and the insulated switch terminals .01 andof, with which the fingers and the carbon contacts of the 4switch engagewhen',

the circuit is closed. The springp serves to open the switch and toraise the armature shaft with the clamp 1', when the currentjs cutoli'from the exciting winding q'offthe electromagnet; Th'eterminal s maybe pr0-' ing into the slot-l of thesle'eveV toprevenf 4 ist y vided fortapping offcu-rient from the cir-` cuit when the switch is closed.

When the winding q is excited,l the-armature efisy strongly attracted,thereby closing the switch and'inoving the clamp rb As a result if the`play between the sleeve lifand the guide posti', the armature shaft bVress.-`

ing on the insulating block e eiects' uniform` pressure between both thecontact fingersv and the switch terminals.- Whenthe current flowingthrough the electromagnet winding g isr interrupted, the s rin p thencompressed, rs.' idlyV raises t e s eeve i. and theswitch b'ri gesecured thereto, the fingers being simultaneously- :separated from theswitch terminals and the carbon contacts finally breaking the circuit.

By disconnecting the armature shaft b fi'oiii the switch bridge, themanner of insulating them is simplified and the switch bridge may befastened directly to the sleeve li. Furthermore, this arrangementprovides the necessary tilting movement of the switch bridge foi'effecting uniform pressure be- .'.tween the-yielding fiiigiisg'tlnd theswitch 4coi'itats'-.uponwclosing -the lcircuit, and for effecting asimultaneous interruption of the circuit at two points when theelectromagnet winding g is dexcited.

Havin thus described my invention, what I c aim is:

1. In an electromagnetic switch, a guide post, a switch'bridge looselmounted on the guide post for axial and tilting movements thereon, anelectromagnetically responsive shaft resting loosely on the switch' bride,-

ing a shaft resting loosely on the switch bridge, anda spring actingbetween the cover and the switch brid e.

3. In an electromagnetic switch, a body portion having an electromagnetwinding positioned in one end thereof, a switch `bridge positionedwithin the other endof the body-portion and having an insulating bearingmember, a cover iiiclosing the switch bridge and carrying switchterminals cooperative therewith, a post secured to the cover, a sleevefastened to the switch bridge and embracing the .post with a slightamount of play, an armature having a shaft passing through theelectromagnct winding and resting upon the bearin r member to engage theswitch bridge with t e switch terminals and a spring acting between thecover and the switch ridge to disengage the switch bridge 'and theswitch terminals upon deexcitation of the electromagnct.

In testimon `wh'eifeof I aiir my signature in presence o two witntsses.

FRANZ KBA/TZ.

Witnesses:

WILLIAM' Stmur, FREDERICK HOYERMANN.

